Physics Corner

The ABS Physics Committee and Q.M. School faculty are preparing template QA forms for popular LDR/HDR brachytherapy procedures. These forms should not be adopted as definitive solutions to regulatory and institutional procedures but as examples to be adapted to your needs. The forms are available to ABS members by clicking this Brachytherapy QA Forms link. Excel worksheets for radiobiological calculations are also in preparation and are available on the page Brachytherapy Guidelines and Consensus Statements.

While air-kerma strength has been a recommended unit of source strength rather than apparent activity for a few decades, mistakes converting from apparent activity have been made. In coordination with the AAPM, the ABS has recommended NRC rulemaking to transition from antiquated units such as apparent activity to traceable quantities such as air-kerma strength. Furthermore, the ABS has proposed refinements in the NRC's proposed rules for medical use of byproduct material, particularly in the definition of medical events.

In addition to the series of forthcoming ABS reports on practice guidelines for GYN, breast, and prostate brachytherapy, there are several published reports of special interest to the brachytherapy physics community:

  • TG-43U1: Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Med Phys 31: 633-674 (2004).

  • TG-43U1S1: Supplement to the 2004 update of the AAPM Task Group No. 43. Med Phys 34: 2187-2205 (2007).

  • TG-137: AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: report of Task Group 137. Med Phys 36: 5310-5322 (2009).

  • TG-138: A dosimetric uncertainty analysis for photon-emitting brachytherapy sources: Report of AAPM Task Group No. 138 and GEC-ESTRO. Med Phys 38: 782-801 (2011).

  • TG-144: Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for90Y microsphere brachytherapy in the treatment of hepatic malignancies. Med Phys 38: 4824-4845 (2011).

  • ASTRO: Definition of medical event is to be based on the total source strength for evaluation of permanent brachytherapy: A report from the American Society for Radiation Oncology. Pract Radiat Oncol 1: 218-223 (2011)

  • TG-129: Dosimetry of 125 I and 103Pd COMS eye plaques for intraocular tumors: Report of Task Group 129 by the AAPM and ABS. Med Phys 39: 6161-6184 (2012).

  • HEBD Working Group: Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO. Med Phys 39: 2904-2929 (2012).


All AAPM Task Group Reports are freely available to the public on their website:

Finally, we would like to remind all of our colleagues of the open invitation to attend the Brachytherapy Physics Committee meetings as held during the ABS Annual Meeting as well as the AAPM annual meeting.

Brachytherapy QA Forms